Drum end closures



C. A. SPEAS DRUM END CLOSURES Oct. 4, 1966 Filed Sept. 26, 1965 4 Sheets-Sheet l @um V INVENTOR CHARLES A. SPEAS ATTORNEY Oct. 4, 1966 c. A. sPEAs 3,276,657

DRUM END CLOSURES Filed Sept. 26,1963 4 Sheets-Sheet 2 INVENTOR CHARLES A. SPEAS BY @MW ATTORNEY Oct. 4, 1966 c. A. sPEAs 3,276,657

DRUM END CLOSURES Filed Sept. 26, 1965 f 4 Sheets-Sheet 3 l INVENTOR CHARLES SPEAS BY @MW ATTORNEY Oct. 4, 1966 c. A. sPEAs DRUM END CLOSURES Filed Sept. 2e, 1963 4 Sheets-Sheet 4 INVENTOR HALES A. SPEAS ATTORNEY United States Patent O 3,276,657 DRUM END CLOSURES Charles A. Speas, Towson, Md., assignor to Hedwin Corporation, New York, N.Y., a corporation of Maryland Filed Sept. 26, 1963, Ser. No. 311,866 Claims. (Cl. 229-5.7)

This invention relates to containers or drums of the type usually embodying side walls of liberboard or the like, provided with top and bottom closures, and used with or without a thin-walled plastic lliner, for the shipment of liquids, pastes, powders and the like. More particularly, the invention consists in new and useful improvements in top and bottom closures for such drums preferably, but not necessarily, composed of thermoformed plastic and formed to facilitate the sound structural attachment of said closures to the drum side walls and to provide built-in reinforcing means which serve the added function of facilitating the vertical stacking of a plurality of containers.

One of the most common liber side wall containers or. drums heretofore in use has been provided with liber 4lids and bottoms, the bottom generally being joined to the side wall by crimping with a steel ring. This structure has proven impractical for the storage of such fiber drums in the open or on wet surfaces, since the fiber absorbs moisture readily and becomes weakened as a result. Also, since the wet surface referred to may be corrosive, it is likely to damage the steel parts of the drum bottom with serious results. Furthermore, conventional drums of liber or ber and steel are often provided with flat bottom surfaces which rest in direct Contact with the oor or palate on which they are Ilocated. Such fiat bottoms not only render it ditiicult to firmly stack a series of drums, but present a potential hazard from nails or other sharp objects projecting from a palate or from some other surface, since such objects can pierce through the at bottom and damage the contents of the drum.

Another objectionable feature which has been observed in conventional drums, especially those having rigid top and bottom closures, is that such closures fail to provide the necessary degree of energy absorption to protect the contents of the drum and to withstand drop testing which is required of drums by certain regulatory agencies, such as the Interstate Commerce Commission.

It is therefore the primary object of the present invention to provide top and bottom closures for drums of Uiiberboard or the like which will overcome the abovenoted disadvantages inherent in conventional drum closures. Y l

Another object of the invention is to provide top and bottom closures for a liberboard drum which are of complementary design so that the bottom of one drum may be readily stacked on the top of an underlying drum and securely held in place against toppling.

Another object of the invention is to provide top and bottom closures having alternate, radially extending, reinforcing ridges and grooves, some of which additionally coact with means for locking superimposed drums in stacked relation.

Still another object of the invention is to provide means for attaching the drum closures in such a manner as to facilitate stapling or stitching, and including means to prevent the tearing of the closure mounting rims at the points of stapling or stitching.

A further object of the invention is to provide top and bottom closures for drums of this nature which, when attached, serve to stitfen the side wall structure of the container against undue flexing.

A still further object is to provide top and bottom closures of a thermoplastic material which is not only "ice moisture-proof, but resists corrosion, and, in addition, provides sutlicient flexibility to absorb energy in the case of drop testing.

With the above and other objects in view which will appear as the description proceeds, the invention consists in the novel features herein set forth, illustrated in the accompanying drawings and more particularly pointed out in the appended claims.

Referring to the drawings in which numerals of like character designate similar parts throughout the several views:

FIG. l is a view of a cylindrical drum in side elevation (partly broken away) showing the top and bottom closures attached;

FIG. 2 is a top plan view of the top closure;

FIG. 3 is a -bottom plan view of the bottom closure;

FIG. 4 is an enlarged fragmentary sectional View taken on line 4-4 of FIG. 2 showing the reinforcing and locking means for stacking;

FIG. 5 is a still further enlarged sectional view taken on line 5 5 of FIG. 2 showing one of the locking lugs;

FIG. 6 is a sectional View through the radial ridges and grooves, taken on line 6-6 of FIG, 2;

FIG. 7 is a sectional view through the bottom closure, taken on line 7 7 of FIG. 3;

FIG. 8 is a similar sectional View showing the complementary relationship between the top and bottom closures in stacked position;

FIG. 9 is a viewlof Ia bottom of a drum similar to that shown in FIG. 8, but including an inner plastic liner;

FIG. 10 is an enlarged fragmentary sectional view showing a modified form of bottom closure mounting rim;

FIG. 11 is a top plan View of a top closure embodying a modified form of the invention as applied to a square or rectangular container; and

FIG. 12 is a perspective View of the modified container.

The preferred form of the invention illustrated in FIGS. 1 to 8 comprises a cylindrical drum 15 of liberboard or the like, having top and bottom closures generally indicated at 16 and 17 respectively. The -top closure v 16, best seen in FIGS. 2 and 4, is preferably formed of an integral piece of semi-rigid thermoplastic material such as polyethylene, althou-gh the important features of the invention are also applicable to top and bottom closures formed of other materials, such as thermosetting plastics, aluminum, steel and iberboard. In this form of the invention, the top closure 16 comprises a circular disc or plate of sutiicient thickness to provide a web 16a of self-sustaining rigidity, while at the same time, having a degree of flexibility. The peripheral edge of the plate is bounded lby and axially inset with respect to yan integral mounting rim 18 which, as seen in FIG. 4, is substantially U-shaped in cross-'section to provide an anular recess 19, designed to receive the circular upper edge of the side wall of the drum or container 15. The outer flange or wall 20 of the rim 18 is extended below the main web portion 16ay of the closure, and intermediate its ends it is provided with a raised annular rib 21 which extends entirely around the llange to serve las a reinforcement against tearing by staples or stitches, as will j hereinafter appear.

' provided with the locking lugs.

downwardly inset both with respect to the rim 18 and the dome 22 and is thermoformed or molded to provide a series of corrugations in the form of reinforcing ridges and grooves 24 and 25 respectively, which radiate from the base of the dome 22 and flare upwardly and outwardly therefrom, terminating integrally with the inner wall of the peripheral rim 18.

Preferably, at three annularly spaced points on the web 16a there are provided three radially disposed locking lugs 26, the upper surfaces of which are upwardly and outwardly inclined from lthe base of the dome 22. These lugs terminate within the radial confines of the rim as at 27 and project vertically at their extremities a predetermined distance beyond the mounting rim 18, where they are integrated with the latter. As will later appear, these locking lugs are designed to coact with a complementary, oppositely inset portion of the bottom closure of an adjacent stacked drum or container.

At a point radially offset with respect to the dome 22, the web 16a may be provided with a flattened circular area 16b which can be removed for the installation of a suitable dispensing closure or attachment.

As will be seen from FIGS. 3 and 7, the bottom closure 17 is generally the same in construction as the top closure 16, with the exception that the bottom `closure is not Thus, the web 17a of the bottom closure is bounded by a mounting rim 28 which is substantially U-shaped in cross-section to receive the lower circular end of the drum wall 15, and its outer flange 29 is provided with an annular reinforcing rib or bead 30 intermediate its extremities. The central portion of the axially inset web 17a is provided with an annular ridge 31 having a central recess 32 of a size to at least partially receive .the cross-shaped dome 22 of the top closure of a drum located beneath, as best seen in FIG. 8. The walls 33 of the ridge 31 are preferably downwardly and outwardly inclined as in the case of the walls 23 of the dome 22.

The web 17a, as in the case of web 16a, is corrugated to provide a series of radially disposed ridges and grooves 34 and 35 respectively, which are tapered outwardly and downwardly from the boundary of the annular ridge 31 to the mounting rim 28, as best seen in FIG. 7. It will be apparent that the main portion of the web 17a, including that portion defining the recess 32, is inwardly offset with respect to the lower extremity of the rim 28.

Both the top closure 16 and the bottom closure 17 may be secured to the respective extremities of the wall of drum by conventional staples or stitches 36 which extend through opposite walls or flanges of the rims 18 and 28 and the intervening Wall portions of drum 15. Due to the inwardly oifset relation of the webs 16a and 17a with respect to the extremities of their rims 18 and 28, as seen in FIGS. 4 and 7, and the alternate arrangement of the radiating grooves and ridges 24, 25, 34 and 35, the operation of stapling or stitching the rims of the closures to the drum wall 15 is facilitated. In other words, by locating the staples, for example, adjacent the outer extremities of the grooves 25 and 35, said grooves can readily accommodate the stapling mechanism without injury to the web. Also, by providing the annular ribs or beads 21 and 30, the walls of the mounting rims are reinforced against tearing by the staples. Normally, when containers of this general type are subjected to unusual strains, such as being dropped from substantial heights, there is a tendency for the rirn of the closure to pull away from the end of the side wall of the container. Certain materials, especially thermoplastics, are easily cut by sharp objects so that there is a tendency for the staple to tear the lid lip or rim, `,and by molding these beads in the outer flanges of the mounting rims, considerable added support is given to the stapled body and the tearing of the rim is prevented.

In FIG. 9, the drum 15 is provided with a thin plastic drum liner 115, especially when liquids, powders, etc. are

to be shipped, and here it will be seen that the central portion of the liner is supported by contact with the central portion 17b of the web 17a which lies within the boundaries of the annular ridge 31 and prevents undue strain on the center of the liner.

In use, it Will be apparent that the structure of the corrugated webs 16a and 17a, as well `as the central dome 22 and complementary annular ridge 31 on the top and bottom closures respectively, reinforce the webs of the closures, and when two drums are stacked one on another, as shown in FIG. 8, the locking lugs 26 on the top closure of the lowermost drum fit within the recessed area of the bottom closure of the uppermost drum, with their outer extremities 27 in abutting relation to the rim 28 of the latter. This prevents lateral sliding movement of one drum with respect to the other, and the locking lugs 26 are so arranged that they are accommodated by the adjacent grooves 35 of the bottom closure 17. Also, the arrangement of the annular ridge 31 of the bottom closure 17 is such that the sagging of the web 17a under the weight of the contents of the upper drum 15 is kept within safe limits by the abutment of the walls of the ridge 31 with the outer walls of the cross-shaped dome 22 of top closure 16 next below. The coaction of the ridge 31 and the dome 22 has a further tendency to supplement the locking of the superimposed drums against lateral displacement.

In the shipment of certain products, especially liquids, it may be desirable to employ a more positive method of sealing the closures to the wall of the container, and such a method is illustrated in FIG. 10. In this embodiment of the invention, the wall 15 of the drum may be coated with a plastic :lilm 15a on the inside or outside surfaces or both. The rim 28 of the closure 17, las in the structures just described, is substantially U-shaped in crosssection, but as distinguished from the previous form, instead of fitting in close surface-to-sur'face contact with the wall of the drum, the recess in the rim is radially enlarged as at 37 and the inner surfaces of both the outer flange 29 and the inner flange 29a of the rim are provided with inwardly projecting, annular ridges which are molded into the plastic. The outer llange 29 is provided with annular ridge 38 and the inner flange 29a with annular ridge 39. The inner flange is also provided with a second annular ridge 40 spaced upwardly from ridge 39, and opposite to ridge 40 the outer flange 29' is molded so that its free extremity 41 is inwardly inclined in opposed relation to the ridge 40, the base 42 of the inclined portion 41 being outwardly offset to provide a reinforcing bead similar to beads 21 and 30 previously described, to thus protect the rim against tearing by the staples 36.

In applying the closure of this form of the invention, the enlarged recess 37 in rim 28 is partially filled with a suitable sealing compound or adhesive 43, and as the lower edge of -the drum wall 15 is forced into the recess 37, it displaces the sealing compound 43 which rises on both sides of the drum wall until it engages the oppositely projecting ridges 38 and 39 which lie in surface contact with the opposite surfaces of the Wall 15. The continued forcing of the drum wall into the .recess and sealing compound tightly compresses the latter against both side surfaces iof the container wall and its escape is prevented by the tight engagement of .the ridges 3S and 39 with the Wall. The staples 36 are then applied which further tightens the engagement of the ridges '38 and 39 with the wall of the drum. The inwardly projecting ridge 40 and inclined end 41 of the ou-ter ilange are likewise forced into close engagement with the wall 15 when the staples are applied.

As previously indicated, the basic principle of this invention may be embodied in a square or rectangular container or-box and such a modilied structure is illustrated in FIGS. 11 and 12. Here it will be seen that top and bottom closures 1'6 land 17 respectively are constructed with radiating ridges Iand grooves 24 and 25 respectively, in the same manner as the top closure shown in FIG. 2. The central portion 22 may or may not -be provided with a dome'as in the other form. The bot-tom closure 17', with the exception lof being rectangular, is generally similar to that shown in FIG. 3 and may or may not have a central ridge comparable to ridge 31 in FIG. 3.

In this particular form of the invention, the .top closure is preferably provided with eight locking lugs 26' and 2'6 equally distributed around the corrugated web, and the four corner lugs 216 are naturally longer than the others bec-ause of the diagonal distance across the closure. In other respects, a drum equipped with this type of top and bottom closures functions in the same manner as that previously described.

In both forms of the invention, it will be apparent that in addition to providing eiectively reinforced top and bottom closures of single thicknesses of formed plastic or other suitable material, the closure design contributes greatly to the rigidity of .the side walls of the drum or box body through the locking effect of the U-sh-aped mounting rims. This greatly reduces the number ott parts required and the amount of labor involved in assembly. Furthermore, the locking lugs which are integrally molded in the plastic top closures, through their mating relation with the bounding rim of the inset bottom closure, greatly facilitates nesting or stacking of a plurality of drums.

It may also be noted that the complementary design of the top and bottom closures and their coacting central domes and annular ridges not only provides the necessary support for the central portion of the bottom of a filled drum, .but through the deflecting action of the web of the bottom closure and the mating engagement of its annular rim with respect to the dome of an underlying top closure, provides a centering action which adds to the locking effect when stacked.

From the foregoing, it is believed that the invention may be readily understood by tho-se skilled in the art without further description, it being borne in mind that numerous changes may be made in the details disclosed without departing from the spirit olf the invention as set forth in the following claims.

I claim:

1. 'In a container adapted to be vertically stacked with similar containers, a -bottom closure comprising a plate formed of a 1material of self-sustaining rigidity bounded by an integral, double-walled mounting rim substantially U-shaped in cross-section to -receive therein the lower end of the wall of said container, the web area of said plate within the contines of said rim being axially inset wi-th respect to the latter, said inset area being formed with a series of radially disposed grooves and ridges, integrally merging at their outer extremities wit-h the inner wall of said rim, a top cl-osure of similar material and dimensions bounded by an integral, double-walled mounting rim substantially U-shaped in cross-section, to receive therein the upper end of the wall olf said container, the area of said top closure within the confines of its rim being axially inset with respect to said rim, said inse-t area being formed with a series of radially disposed grooves and ridges integrally merging at their outer extremities with the inner wall of said last-named rim, the inset area of said top closure being provided at selected annularly spaced points with a plurality of radially disposed locking lugs which project axially beyond the limits of said last-named rim with their -outer ends terminating within the radial contines of said last-named rim, whereby when the Ibottom closure of one container is stacked upon the top closure of an underlying container, the locking lugs of the latter are received within the inset area of the forme-r, with the outer extremities of said locking lugs in radially abutting relation to the inner wall olf the superimposed bottom `closure rim to prevent lateral displacement of the stacked containers.

2. A structure as claimed in claim 1, wherein the central portion of the web of said bottom closure is provided with a concentric, recessed ridge, the corresponding area of said top closure web being provided with a concentric projecting dome of dimensions -to be at least partially received within the central recess of the bo-ttom closure ridge of a superimposed container, whereby upon the flexing of said superimposed bottom closure under the weight .of the contents of its drum, the bottom closure of the upper drum .is supported by the top closure of the lower drum, and relative lateral displacement of the two is prevented. v

3. In a container adapted to be vertically stacked with similar containers, a bottom closure comprising a plate formed of a material of self-sustaining rigidity bounded by an integral, double-walled mounting rim substantially U-shaped in cross-section to receive therein the lower end of the wall of said container, the web area of said plate within the confines of said rim being axially inset with respect to the latter, said inset area being formed with a series of radially disposed grooves and ridges, integrally vmerging at their outer extremities with the inner wall of said mounting rim, a top closure of similar material and dimensions, bounded by .an integral, double-walled mounting rim substantially U-shaped in cross-section to receive `therein the upper end of the wall of said container, the

area of said top closure Within the contines of its rim being axially inset with respect to said rim, said inset area being formed with a series of radially disposed grooves and ridges integrally merging at their outer extremities with the inner wall of said las-t-named rim, securing means extending through each of said double-Walled mounting rims and the intervening container wall, a raised, annular reinforcing bead on the outer walls of each rim, lying between the extremities thereof land said securing means to prevent tearing off said rims, the inset area of said top closure being provided at selected, annularly spaced points with a plurality of radially disposed locking lugs which project axially beyond the limits of said last-named rim, with their outer ends terminating within the radial contines of said last-named rim, whereby when the bottom closure of one container is stacked upon the top closure of an underlying container, the locking lugs of the latter are received within the inset area of the former, with the outer extremities of said locking lugs in radially abutting relation t-o the inner wall of the superimposed bottom closure rim to prevent later-al displacement of the stacked containers.

4. A structure as claimed in claim 3, wherein the upper surfaces of said radiating ribs and locking lugs are inclined from their inner to their outer extremities.

5. In a container adapted to be vertically stacked with similar containers, bottom and top closures each comprising a plate formed of a semi-exible material of self-sustaining rigidity bounded by an integral, double-walled mounting rim substantially U-shaped in cross-section to receive the respective ends of the wall of said container, the web areas of said plates within the connes of respective rims being axially inset with respect to said rims, said inset areas being formed with a series of radially disposed ridges with intervening grooves, integrally merging at their outer extremities with the inner walls of respective rims, said ridges being inwardly spaced from the extremities of respective rims, the top closure being additionally provided in its inset area with 4a plurality of annularly spaced, radially disposed locking lugs which project axially beyond the limits of its mounting rim, with their outer ends terminating within the radial connes of said last-named rim, whereby when the bottom closure of one container is stacked upon the top closure of an underlying container, the locking lugs ofthe latter are received within the inset area of the former, with the outer extremities of said locking lugs in radially abutting relation to the inner wall of the superimposed bottom closure rim to prevent lateral displacement ofthe stacked containers.

6. A structure as claimed in claim 5, including securing means extending through each of said double-walled mounting rims and the intervening container Wall, and a raised, annular reinforcing bead on the outer wall of each rim, lying between the extremities thereof and said securing means to prevent tearing of said rims.

7. A structure as claimed in claim 5, wherein the mounting rim of at least said bottom closure is provided with a radially enlarged area adapted to receive a sealing compound, the inner surfaces of the inner and outer wall of said rim being formed with oppositely projecting, annular ridges adapted to engage the respective opposed surfaces of the container wall, whereby when said container wall is forced into said spaced area containing sealing compound, said oppositely disposed ridges serve to maintain said sealing compound within said recess and in sealing engagement with said container wall.

8. A structure as claimed in claim 5, wherein said container is provided with an inner plastic liner, said bottom closure being formed with a central liner supporting member bounded at its outer extremities by a downwardly projecting, centrally recessed rim, said top closure being provided concentric with said rim with an upwardly projecting dome adapted to coact with the central rim of a superimposed bottom drum closure to limit the flexing of the latter, and, at the same time, serve to lock the two adjacent closures against lateral displacement.

9. In a container adapted to be vertically stacked with similar containers, bottom and top closures of equal diameters, each comprising a plate formed of a semi-exible material of self-sustaining rigidity bounded by an integral, double-walled mounting rim substantially U-shaped in cross-section to receive the respective ends of the wall of said container, the web areas of said plates within the connes of respective rims being axially inset with respect to said rims, the top closure being provided in its inset area with a plurality of integral, annularly spaced, radially disposed locking lugs which project axially beyond the limits of its mounting rim, with their outer ends terminating within the radial contines of said last-named rim and integral therewith, whereby when the bottom closure of one container is stacked upon the top closure of an underlying container, the locking lugs of the latter are received within the inset area of the former, with the outer extremities of said locking lugs in radially abutting relation to the inner wall of the superimposed bottom closure rim, lto prevent lateral displacement of the stacked containers.

10. A structure as claimed in claim 5, wherein the central portion of the inset area of one closure is provided with a concentric, centrally recessed ridge, the corresponding area of the other closure being provided with a concentric projecting dome of dimensions to be at least partially received within and supported by the recessed closure ridge of a vertically adjacent, stacked drum, whereby upon the flexing of the bottom closure of an upper stacked drum under the weight of its contents, said bottom closure is supported by the Vtop closure of an underlying drum and lateral displacement of the two is prevented by the nesting of the dome of one closure Within the recessed ridge of the other closure.

References Cited by the Examiner UNITED STATES PATENTS 526,940 10/1894 Pettit et al. 2,822,952 2/ 1958 Scott 220-97 2,912,136 11/1959 Redmond et al 220-63 2,951,613 9/1960 Hardigg 220-80 3,070,257 12/ 1962 Bojanowski 220-97 3,147,879 9/1964 Scholtz 220-97 X 3,179,321 4/1965 Carpenter 229-57 3,207,359 9/ 1965 Heisler et al. 220-97 THERON E. CONDON, Primary Examiner.

G. E. LOWRANCE, Assistant Examiner. 

1. IN A CONTAINER ADAPTED TO BE VERTICALLY STACKED WITH SIMILAR CONTAINERS, A BOTTOM CLOSURE COMPRISING A PLATE FORMED OF A MATERIAL OF SELF-SUSTAINING RIGIDITY BOUNDED BY AN INTEGRAL, DOUBLE-WALLED MOUNTING RIM SUBSTANTIALLY U-SHAPED IN CROSS-SECTION TO RECEIVE THEREIN THE LOWER END OF THE WALL OF SAID CONTAINER, THE WEB AREA OF SAID PLATE WITHIN THE CONFINES OF SAID RIM BEING AXIALLY INSET WITH RESPECT TO THE LATTER, SAID INSET AREA BEING AXIALLY INSET WITH A SERIES OF RADIALLY DISPOSED GROOVES AND RIDGES, INTEGRALLY MERGING AT THEIR OUTER EXTREMITIES WITH THE INNER WALL OF SAID RIM, A TOP CLOSURE OF SIMILAR MATERIAL AND DIMENSIONS BOUNDED BY AN INTEGRAL, DOUBLE-WALLED MOUNTING RIM SUBSTANTIALLY U-SHAPED IN CROSS-SECTION, TO RECEIVE THEREIN THE UPPER END OF THE WALL OF SAID CONTAINER, THE AREA OF SAID TOP CLOSURE WITHIN THE CONFINES OF ITS RIM BEING AXIALLY INSET WITH RESPECT TO SAID RIM, SAID INSET AREA BEING FORMED WITH A SERIES OF RADIALLY DISPOSED GROOVES AND RIDGES INTEGRALLY MERGING AT THEIR OUTER EXTREMITIES WITH THE INNER WALL OF SAID LAST-NAMED RIM, THE INSET AREA OF SAID TOP CLOSURE BEING PROVIDED AT SELECTED ANNULARLY SPACED POINTS WITH A PLURALITY OF RADIALLY DISPOSED LOCKING LUGS WHICH PROJECT AXIALLY BEYOND THE LIMITS OF SAID LAST-NAMED RIM WITH THEIR OUTER ENDS TERMINATING WITHIN THE RADIAL CONFINES OF SAID LAST-NAMED RIM, WHEREBY WHEN THE BOTTOM CLOSURE OF ONE CONTAINER IS STACKED UPON THE TOP CLOSURE OF AN UNDERLYING CONTAINER, THE LOCKING LUGS OF THE LATTER ARE RECEIVED WITHIN THE INSET AREA OF THE FORMER, WITH THE OUTER EXTREMITIES OF SAID LOCKING LUGS IN RADIALLY ABUTTING RELATION TO THE INNER WALL OF THE SUPERIMPOSED BOTTOM CLOSURE RIM TO PREVENT LATERAL DISPLACEMENT OF THE STACKED CONTAINERS. 